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aba12d.cpp
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aba12d.cpp
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// 2014-09-22
#include <vector>
#include <algorithm>
#include <cstdio>
using namespace std;
bool is_knumber[1000001];
int knumber_count[1000001];
bool is_prime(int x) {
if (x < 2) return false;
for (int i = 2; i*i <= x; i++) {
if (x%i == 0) return false;
}
return true;
}
int main() {
is_knumber[2] = true;
for (int i = 2; i <= 1000; i++) {
if (is_prime(i)) {
int pwr = i*i;
int sod = 1 + i + i*i;
while (pwr <= 1000000) {
if (is_prime(sod)) {
is_knumber[pwr] = true;
}
pwr *= i;
sod += pwr;
}
}
}
knumber_count[0] = 0;
for (int i = 1; i <= 1000000; i++) {
knumber_count[i] = knumber_count[i-1] + int(is_knumber[i]);
}
int T; scanf("%d", &T);
while (T--) {
int A, B; scanf("%d %d", &A, &B);
printf("%d\n", knumber_count[B] - knumber_count[A-1]);
}
return 0;
}